I see that a few core updates like kernel and xorg are kept out if you leave level 4 and 5 update unchecked in the update manager. This is the default setting. I am wondering how that will work on a rolling release. At some point the kernel will be too old for the rest of the system since there's no full upgrade through releases like with other versions of Mint. Will the kernel updates and such be "downgraded" to level 1 - 3 at some point to accommodate the rolling release principle? I'm trying to understand how this is going to work over time, so any clarification on this would be great.

I've been taking the level 4 & 5 updates myself, and haven't had any big issues. I'm still wondering how to enable more than 1 kernel option so one can go to the previous kernel as a fallback if needed, but maybe it's not a grub2 option or something. (I started a thread about it, so I'll post follow-up q's over there...)

I think your question is quite valid. Sometimes before I've taken a level 4 or 5 update I'll hold off a couple of days and see if anything is posted on the forums or the blog first. If nothing specific is posted I just go with the updates for the reasons you state. I think we're all somewhat pioneers on this edition of Mint, so there aren't any clear-cut answers and we all have to do what we're comfortable with and hope for the best. And make sure you have backups of your important 'stuff'.

So far for me it's been working great, but we'll see what happens when Squeeze is released and a whole batch of new updates hit the testing repo''s.